Same problem with me. I recently bought a Band Hero bundle, and the Guitar (from GH5) wont sync. Everything blinks, but the dongle and guitar wont match up. Someone who has had this problem, please explain how you solved it. I tried contacting Activision, but its impossible to get a hold of them.

I recently bought my GH5 guitar.... same problem... cant manage to sync it with the dongle... I checked every troubleshooter there is on Internet, all around google.. tried everything, nothing works... I guess I have a defective guitar. Did u manage to somehow fix this problem >>>?????

ACTIVISION AUTHORIZES USE OF THIS GUITAR HERO GAME ONLY IN COMBINATION WITH GUITAR HERO CONTROLLERS PROVIDED BY ACTIVISION OR OTHER AUTHORIZED CONTROLLERS OR, IF APPLICABLE, STANDARD GAMEPAD CONTROLLERS PROVIDED WITH THE GAME CONSOLE. ACTIVISION ALSO AUTHORIZES USE OF THIS GUITAR HERO CONTROLLER ONLY WITH A GUITAR HERO GAME PRODUCT OR OTHER AUTHORIZED PRODUCT. ANY OTHER USE IS PROHIBITED AND NO OTHER LICENSE, EXPRESS OR IMPLIED, IS GRANTED.